Electronic device

Abstract

An electronic device including: a reference voltage generator circuit to generate a reference voltage based on a first and second voltage, the reference voltage generator circuit including: a first current source to supply a first current to each of a first and second node; an amplifier to amplify a difference between the first voltage of the first node and the second voltage of the second node and to output a difference voltage corresponding to the amplified difference; a first bipolar junction transistor (BJT) connected to the first node; a first resistor connected to the second node; a second BJT connected between the first resistor and ground; a second resistor connected between the second node and ground; and a first transistor to be supplied with a second current from the first current source; and an adaptive cascode circuit to generate a bias voltage applied to a gate of the first transistor.

What is claimed is: 
     
       1. An electronic device, comprising:
 a reference voltage generator circuit configured to generate a difference voltage and a reference voltage based on a first voltage of a first node and a second voltage of a second node; and 
 an adaptive cascode circuit configured to generate a bias voltage based on the difference voltage, 
 wherein the reference voltage generator circuit includes: 
 a first transistor including a gate to which the bias voltage is applied from the adaptive cascode circuit; and 
 a first current source configured to supply a first current to each of the first node and the second node and to supply a second current to the first transistor, 
 wherein the adaptive cascode circuit includes: 
 a second current source configured to output a third current and a replica current; 
 a voltage buffer configured to generate the bias voltage based on the third current; 
 a current mirror configured to mirror the third current; and 
 a replica circuit configured to be implemented as a replica of one or more components of the reference voltage generator circuit, and 
 wherein the voltage buffer includes: 
 a second transistor including a gate to which the bias voltage is applied and a second terminal to which the bias voltage is applied; and 
 a third transistor including a gate to which the bias voltage is applied. 
 
     
     
       2. The electronic device of  claim 1 , wherein the reference voltage generator circuit further includes an amplifier configured to generate the difference voltage by amplifying a difference between the first voltage and the second voltage,
 wherein the first current source includes: 
 a first source transistor connected to the first node and to which the first current is supplied; 
 a second source transistor connected to the second node and to which the first current is supplied; and 
 a third source transistor including a gate connected to an output terminal of the amplifier and to which the second current is supplied, and 
 wherein a first terminal of the third source transistor is connected to a first terminal of the first transistor. 
 
     
     
       3. The electronic device of  claim 2 , wherein the first voltage, the second voltage, and a third voltage, which is applied to the first terminal of the first transistor, are the same. 
     
     
       4. The electronic device of  claim 1 , wherein the reference voltage generator circuit further includes an amplifier configured to generate the difference voltage by amplifying a difference between the first voltage and the second voltage, and
 wherein the second current source includes: 
 a fourth transistor including a gate connected to an output terminal of the amplifier and configured to receive the difference voltage and to output the third current and the replica current in response to the difference voltage; and 
 a fifth transistor including a gate connected to the output terminal of the amplifier and configured to receive the difference voltage and to output the third current in response to the difference voltage. 
 
     
     
       5. The electronic device of  claim 4 , wherein an amount of the third current is the same as an amount of the second current. 
     
     
       6. The electronic device of  claim 1 , wherein a voltage applied to the first terminal of the second transistor, a voltage applied to a first terminal of the third transistor, and a voltage applied to a first terminal of the first transistor are the same. 
     
     
       7. The electronic device of  claim 1 , wherein the current mirror includes:
 a sixth transistor including a first terminal to which the bias voltage is applied and a second terminal connected to a ground terminal; and 
 a seventh transistor including a gate connected to a gate of the sixth transistor, a first terminal connected to the gate of the sixth transistor, and a second terminal connected to the ground terminal. 
 
     
     
       8. The electronic device of  claim 7 , wherein a size of the sixth transistor is the same as a size of the seventh transistor. 
     
     
       9. The electronic device of  claim 1 , wherein the second current source includes a fourth transistor configured to output the replica current, and
 wherein the replica circuit includes: 
 an eighth transistor connected between the fourth transistor and a ground terminal; and 
 a first resistor connected in parallel with the eighth transistor. 
 
     
     
       10. The electronic device of  claim 9 , wherein the fourth transistor supplies the replica current to the eighth transistor, an amount of the replica current being the same as an amount of the first current. 
     
     
       11. The electronic device of  claim 9 , wherein the reference voltage generator circuit includes a first bipolar junction transistor (BJT) connected between the first node and the ground terminal,
 wherein the eighth transistor is implemented with a BJT, and 
 wherein an emitter-base voltage of the eighth transistor is the same as the emitter-base voltage of the first BJT. 
 
     
     
       12. An electronic device, comprising:
 a reference voltage generator circuit configured to generate a difference voltage and a reference voltage based on a first voltage of a first node and a second voltage of a second node; 
 an adaptive cascode circuit configured to generate a bias voltage based on the difference voltage; and 
 a start-up circuit configured to supply, to the adaptive cascode circuit, a start-up voltage for adjusting a magnitude of the bias voltage, 
 wherein the reference voltage generator circuit includes: 
 a first transistor including a gate to which the bias voltage is applied from the adaptive cascode circuit; and 
 a first current source configured to supply a first current to each of the first node and the second node and to supply a second current to the first transistor, and 
 wherein the adaptive cascode circuit includes: 
 a second current source configured to output a third current and a replica current; 
 a voltage buffer configured to generate the bias voltage based on the third current; 
 a current mirror configured to mirror the third current; and 
 a replica circuit configured to be implemented as a replica of one or more components of the reference voltage generator circuit. 
 
     
     
       13. The electronic device of  claim 12 , wherein the first voltage, the second voltage, and a voltage of a first terminal of the first transistor, which is connected to the first current source, are the same. 
     
     
       14. The electronic device of  claim 12 , wherein the reference voltage generator circuit includes a first bipolar junction transistor (BJT) connected between the first node and a ground terminal, and
 wherein the adaptive cascode circuit compensates for a change of an emitter-base voltage of the first BJT, which occurs due to a temperature change, by using the bias voltage. 
 
     
     
       15. The electronic device of  claim 12 , wherein the adaptive cascode circuit includes:
 a second transistor including a first terminal connected to the gate of the first transistor and a gate to which the start-up voltage is applied. 
 
     
     
       16. The electronic device of  claim 15 , wherein the start-up voltage has a magnitude the same as a magnitude of a driving voltage, which is supplied to the electronic device, from when the electronic device is initialized to a first time when a magnitude of the reference voltage corresponds to a first level, and has a magnitude the same as a magnitude of a ground voltage after the first time. 
     
     
       17. The electronic device of  claim 12 , wherein the voltage buffer includes:
 a third transistor including a gate to which the bias voltage is applied and a second terminal to which the bias voltage is applied; and 
 a fourth transistor including a gate to which the bias voltage is applied and through which the third current flows, an amount of the third current being the same as an amount of the second current, and 
 wherein the replica circuit includes a replica transistor supplied with the replica current and to which the first voltage is applied, an amount of the replica current being the same as an amount of the first current. 
 
     
     
       18. A regulator circuit, comprising:
 a reference voltage generator circuit configured to generate a reference voltage based on a first voltage and a second voltage, the reference voltage generator circuit including: 
 a first current source configured to supply a first current to each of a first node and a second node; 
 an amplifier configured to amplify a difference between the first voltage of the first node and the second voltage of the second node; and 
 a first transistor supplied with a second current from the first current source, 
 an adaptive cascode circuit configured to generate a bias voltage to be applied to a gate of the first transistor; 
 a start-up circuit configured to supply, to the adaptive cascode circuit, a start-up voltage for adjusting a magnitude of the bias voltage; and 
 an error amplifying circuit configured to output a regulated voltage, the error amplifying circuit including: 
 an error amplifier configured to generate the regulated voltage by amplifying a difference between voltages applied from each of a first input terminal and a second input terminal; 
 a first register connected between an output terminal of the error amplifier and a fourth node; and 
 a second register connected between the fourth node and a ground terminal, 
 wherein the second input terminal is connected to the fourth node, 
 wherein the reference voltage is applied to the first input terminal, and a fourth voltage of the fourth node is applied to the second input terminal, and 
 wherein the first voltage, the second voltage, and a voltage of a first terminal of the first transistor, which is connected to the first current source, are the same. 
 
     
     
       19. The regulator circuit of  claim 18 , wherein the reference voltage generator circuit includes a first bipolar junction transistor (BJT) connected between the first node and a ground terminal, and
 wherein the adaptive cascode circuit compensates for a change of an emitter-base voltage of the first BJT, which occurs due to a temperature change, by using the bias voltage. 
 
     
     
       20. The regulator circuit of  claim 18 , wherein the adaptive cascode circuit includes:
 a second transistor including a first terminal connected to the gate of the first transistor and a gate to which the start-up voltage is applied.